A bill passed this week by the state House designed to guarantee more insurance coverage for motorists will likely result in higher premiums for people who can least afford it, critics of the legislation say.

On Tuesday, the House approved increasing the minimum liability coverage that drivers are required to buy to $25,000 for bodily injury for each person injured in a wreck, $50,000 for all people injured and $25,000 to cover property damage.

The existing requirements are $15,000, $30,000 and $10,000, respectively.

The measure means motorists will have to buy more car insurance to stay legal. Premiums could increase 10 percent to 20 percent, or up to $100 a year extra for minimum coverage. experts say.

"It would definitely mean an increase in premiums for people who currently have minimum coverage," said Allison Dean Love, executive director of the South Carolina Insurance News Service, an industry group.

The legislation now goes to Gov. Mark Sanford for his signature.

The provision was an amendment to a bill that addressed a state Supreme Court decision about what insurance agents are required to do when offering insurance.

House Speaker Bobby Harrell, R-Charleston, said most House members felt current minimum coverage requirements were too low. Harrell, an insurance agent, said most of his customers already buy more coverage than that.

The amendment was offered by Sen. Gerald Malloy, D-Hartsville, who is president of the South Carolina Trial Lawyers Association. The bill, which passed with little discussion on the House floor, could be a boon for attorneys who deal in personal injury claims.

A spokesman for the governor's office said there are serious concerns that the bill passed so hastily.

"It's obscene that political decisions in the legislature are often driven by people who stand to gain financially," said spokesman Joel Sawyer.

Malloy said an increase was long overdue. Minimum coverage requirements have not increased since 1974, he said, except for a property damage increase in 1997. The move is a protective measure for motorists, he said, and not designed to line attorneys' pockets.

"It has been voted on by all members of the House and the Senate," Malloy said. "Mr. Sawyer is misdirected. His response is disingenuous."

The Property Casualty Insurers Association of America had urged legislators to oppose the bill, claiming insurance premiums would increase for many consumers and put more uninsured motorists on the highways.

The increase will hit low-income people the hardest, the association said. Some drivers will be forced to violate the law and drive without insurance because they can't afford the higher premiums.

As the number of uninsured drivers rises, it increases costs for responsible drivers who have to pay more for uninsured motorist coverage, said Robert Herlong, the association's vice president and regional manager.

Although the goal is to protect more people, he said, the result will be to increase uninsured motorists and put more people at risk.

"One of our key concerns about this legislation is that it will cause double-digit price increases for thousands of consumers who are least likely to be able to afford this increase," Herlong said.

Reach Peter Hull at 937-5594 or phull@postandcourier.com.

The Associated Press contributed to this report.